Chapter 16, Problem 104QRT

Explain how the entropy of the universe increases when an aluminum metal can is made from aluminum ore. The first step is to extract the ore, which is primarily a form of A1₂O₃, from the ground. After it is purified by freeing it from oxides of silicon and iron, aluminum oxide is changed to the metal by an input of electrical energy.

${\text{2Al}}_{\text{2}}{\text{O}}_{\text{3}}\text{(s) }\underset{\to }{\text{electrical energy}}{\text{ 4 Al(s) + 3 O}}_{\text{2}}\text{(g)}$